Eugene Volokh takes a look at a case where duty to retreat did play into a case. In this case, the man who failed to retreat from someone threatening his life got 18-20 years in prison. The man was also black:
Again, the question was: Did the victim’s “I’m going to stab you n[-----]” require defendant to give up the right to be where he was, or else be legally stripped of the right to defend himself with deadly force if he stayed? (I infer that he was on a sidewalk or a place that’s similarly open to the public, and not on the threatener’s property, or else the court would have noted that [...)]
Bracketed part I edited, as to avoid tripping anyone’s keyword filters and for brevity. Read the whole thing. There have been a lot of accusations from blowhards like Sharpton that the Florida law is a license for white people to kill black people, when in reality the law will probably protect more blacks than whites, simply due to the fact that blacks live in areas where the need to defend oneself tends to be more acute. In this case, Mr. Benoit ended up in prison. Our opponents say these cases don’t exist, but they do. It just often happens to people who don’t have the money to hire PR firms to make their cases to the public.